Flávio Bolsonaro's winning margin narrows

A win by four to eight points trades at 32%, as a thinner win prices higher.

In one line: The brackets put most weight on a Flávio win under 4 points, and the 4-8 band keeps losing ground.

Traders cut the odds on Flávio Bolsonaro winning Brazil's second round by four to eight points. The contract fell from 52% on 7 Oct to 32% on 14 Oct, a drop of 20 points over the 7 days and 12.5 points in the last 24 hours, per the venue's own figure. It hit 60% on 8 Oct and touched 31% on 14 Oct.

The other contracts in the same event lean the other way. A Flávio win by less than 4% prices at 36%, 8-12% sits at 13% and at least 12% at 3%. Lula's margin contracts run from 0% in the top two bands to 13% for under 4%, which is best read as the mirror of a close Flávio win rather than a live Lula path.

The squeeze comes from below. The under-4% band prices higher than this 4-8 band, 36% against 32%, so the market's own weights say a thinner Flávio win is the likelier one. Traders are not abandoning Flávio for Lula; Flávio still wins outright on Polymarket at 85% and on Kalshi at 86%. The doubt is margin, not winner. The cross-venue line pairing Polymarket's 32% with Kalshi's 0% on Eduardo Bolsonaro compares two different questions and says nothing about this contract.

On the market's own weights the 4-8 band looks overpriced against the under-4% contract, and the contract fell 20 points over the seven days. A four-to-eight-point Flávio win on 25 Oct looks less likely than not.

The call: this contract resolves NO, and the 32% underrates that risk. What would prove it wrong is a polling release, dated before 25 Oct, that shows Flávio four to eight points clear.